Direct Evidence for Coupled Surface and Concentration Quenching Dynamics in Lanthanide-Doped Nanocrystals

Luminescence quenching at high dopant concentrations generally limits the dopant concentration to less than 1–5 mol% in lanthanide-doped materials, and this remains a major obstacle in designing materials with enhanced efficiency/brightness. In this work, we provide direct evidence that the major quenching process at high dopant concentrations is the energy migration to the surface (i.e., surface quenching) as opposed to the common misconception of cross-relaxation between dopant ions. We show that after an inert epitaxial shell growth, erbium (Er3+) concentrations as high as 100 mol% in NaY(Er)F4/NaLuF4 core/shell nanocrystals enhance the emission intensity of both upconversion and downshifted luminescence…

• UD
  U.S. Department of Energy
• NI
  National Institutes of Health
• NO
  NIH Office of the Director

  Award: DP2 OD006499
• NE
  National Eye Institute

  Award: 5 R01 EY024134-02
• BE
  Basic Energy Sciences

  Award: DE-AC02-05CH11231